Recently, in a semiconductor chip mounting method on a substrate, it has currently been under consideration of using, for the purpose of shortening process, “prior supply type underfill film” in which an underfill film is stuck on a substrate, prior to metallic bonding or pressure welding bonding of a semiconductor Integrated Circuit (IC) electrode and a substrate electrode.
The mounting method utilizing the prior supply type underfill film is, for example, effectuated as in the flowing (see, for example, Patent Document 1).
The method involves:
Step A: laminating an underfill film to a wafer and dicing the wafer to fabricate a semiconductor chip;
Step B: positioning the semiconductor chip on the substrate; and
Step C: pressure bonding the semiconductor chip and the substrate, under high temperature and high pressure, to ensure secure conduction by metallic bonding of a solder bump, and adhering the semiconductor chip to the substrate by a curing action of the underfill film.
Regarding such a mounting method, Patent Document 2 proposes, for example, enhancing wettability of a solder and improving a bonding state thereof by using an adhesive having a flux effect.
However, the conventional underfill film entails a problem that a solder wet spreads to a solder-adhered electrode side, and precludes the film from providing good bonding with an opposing electrode.